This condition causes the body to produce too many of the white blood cells (eosinophils) that help to protect the body from infection. These high levels indicate that the patient may be reacting to an allergen or a parasite, or to substances produced by cancer cells related to Hodgkin’s disease and chronic myeloid leukemia.
There are three types of eosinphilia:
- Familial eosinophilia is caused by a mutation in the genes that control eosinophil growth
- Secondary eosinophilia is related to a parasitic infection, autoimmune reaction, allergic, or other inflammatory illnesses
- Primary eosinophilia is related to certain leukemias and to myelodysplastic syndromes (MDS).
The two main types of primary eosinophilia are chronic eosinophilic leukemia and a lymphoproliferative disorder. Chronic eosinophilic leukemia is caused by a mutation in the platelet-derived growth factor receptor gene. This can often be treated effectively with imatinib (Gleevec) a medicine that is often used for chronic myeloid leukemia, but also targets the platelet-derived growth factor protein. When eosinophilia is caused by a lymphoproliferative disorder, it can be treated with corticosteroids or with interferon, a drug that has effects on the bone marrow and the immune system.